With the looming CAFE fuel economy standards, just about every automaker out there is pushing hard to migrate from larger displacement engines to engines with a smaller displacement, typically using a turbocharger to get the same sort of power output. The benefit of this is that it allows drivers to have the same performance with improved fuel economy.

One of the most successful automakers at making this transition away from higher displacement engines has been Ford with its line of EcoBoost power plants. Detroit News reports that Ford is projecting an increase in sales for vehicles using four-cylinder engines and that by 2020 66% of all new vehicles will use smaller displacement four-cylinder engines.

"I think it's maybe a stretch. But I don't find it implausible," said Bill Visnic, senior editor at the car research site Edmunds.com, in a telephone interview. "If you look at where things have been going segment by segment, except pickups, you could say that's been the trend."

In 2008, only 40% of new vehicles sold used four-cylinder engines compared to 53% today. Currently, the majority of small and medium-size cars on the automotive market come standard with a four-cylinder engine. Most compact SUVs also come standard with four-cylinder engine. Full-size pickups and full-size SUVs currently come with six and eight-cylinder engine options. In 2012, sales of pickup trucks accounted for 13% of all new market sales.

Mike Osmotoso of LMC Automotive notes that to achieve that 66% goal, "[Ford would be] expecting pickups and full-size SUVs to virtually disappear."

quote: This is just my long-winded way of saying the weight of the pick-up truck as very little to do with the towing capacity.

Complete rubbish.

In order to safely brake and simultaneously turn the vehicle, you need to ensure that there is not an overly large reliance on the trailer brakes and that the tractor retains sufficient authority over the drawbar.

If you have enough time and you're REALLY that interested, I can go into how you rate brakes and the entire braking system if you REALLY want to know.

And I can spend probably just as much time on the very closely related brake force calculations/engineering aspect of the entire braking system (which is probably part of the rating seminar anyways...). And then we can finally put the final piece of the puzzle by letting the mass of the vehicle be a variable rather than a fixed, constant value in the computations, and if you head hasn't exploded at that point, this probably will. :oD

DISCLAIMER: The views and opinions expressed here are solely that of my own and are not representative of Ford Motor Company or its affiliates.

So I'll entertain this thought exercise of yours for a moment and run with the hypothetical:

If your trailer has EBD (which is really just another version of glorified ABS), how would you prevent the trailer yaw rate due to EBD from being HIGHER than your the yaw rate of your lead towing pickup?

And if you have a 4000 lb pickup towing a 6000 lb boat, what's the weight transfer during braking? So how much would EBD really be able to help you? How would you coordinate the trailer EBD to the towing pickup's EBD?

Think about what you're suggesting...how would you pull it off?

DISCLAIMER: The views and opinions expressed here are solely that of my own and are not representative of Ford Motor Company or its affiliates.

quote: In order to safely brake and simultaneously turn the vehicle, you need to ensure that there is not an overly large reliance on the trailer brakes and that the tractor retains sufficient authority over the drawbar.

Complete garbage (see I can do that too).

If you're towing a load that's greater than the tow vehicles GVWR, which if you're towing anything you are, you ARE overly relying on the trailers brakes! LOL! The tow vehicle is NOT designed to brake anything over its own GVWR. The trailers brakes are explicitly for that purpose. In order to brake and turn safely with a towed load, you just need to slow the f$&k down!

When braking, you actually want the trailers to rely most of its braking power on the towing vehicle. This is to maintain more control. If the trailer is actually braking faster than the truck, then you lose control. It's a safety thing but you shouldn't brake and turn anyways, it's just unsafe.

In order brake and turn safely with any vehicle, you just need to slow down before the turn.

Yes and that proves his point that trailers rely on vehicle brakes and tow vehicles are designed with that in mind.

quote: Yes you want the combined braking power and yes it makes for stable braking but the not designed for over GVWR braking is still is a fact.

that's why there's a max tow limit and any trailers past a certain weight has to have brakes. The max tow weighs depends on how much braking the vehicle can provide along with vehicle. It cannot pass a certain %. If the vehicle has a low GVWR then it will have a lower tow limit. That's why the same vehicle with double wheels in the back have a higher GVWR and tow rating. Nothing changed except grip and braking capabilities.

If it's based on combined braking power then there wouldn't be a tow limit because the only variable would be trailer braking power. that wouldn't make any sense and your vehicle would be very unsafe.

Gross Axle Weight Rating (gawr): The total allowable weight on an individual axle. This includes the weight of the tires, wheels, brakes and the axle itself.

Maximum Tow Rating: The manufacturer’s weight limit for towed loads. For conventional trailers, this normally includes a hitch-weight limit as well; for fifth-wheels, the pin weight is applied to the truck’s gvwr and its rear-axle gawr.

quote: Yes and that proves his point that trailers rely on vehicle brakes and tow vehicles are designed with that in mind.

No that only proves law makers can make laws.

quote: that's why there's a max tow limit and any trailers past a certain weight has to have brakes.

Max tow limits are determined by the manufacturer and state and local regulations. Max tow on my pickup is 16,000 lbs with a 5th wheel/gooseneck and 10k lbs with a bumper hitch. In CA, trailers over 1500 lbs require brakes. Other states are higher. Tow rating isn't based on GVWR, it's based on the weight handling capacity of each axle/tire. It just so happens that heavy axles contribute to a higher overall weight and in turn more GVWR.

Uh...half-truth. I haven't gone through and dissected all of the trailer tow calculations yet for work (that's coming up shortly) but from what I've been told, the relationship between trailer tow (weight capacity) and GVWR is not that straightforward.

There are a LOT of conditions regarding how you calculate trailer tow, how you rate it, and how those ratings relate to the GVWR of a vehicle.

Here is the old way of calculating conventional trailer tow capacity (I'm in the process of rewriting this anyways, hence why I'm researching or will be researching the trailer tow government regulations/stuff shortly):

=IF(OR(ISBLANK(ttlimit),ISBLANK(tongue_cg),ISBLAN K(tongue_per),ISBLANK(gcwr11)),"-",FLOOR((MIN((gvw- (ttcurb1+ttc1))/tongue_per,((rmaxgawr-((ttcurb1+ttc 1)-(ttcurbfrt1+ttcfrt1)))*wb)/(tongue_cg-zeroline)/ tongue_per,gcwr11-ttcurb1-ttc1,ttlimit)),ttround))< br />And that's just ONE of the calculations. Note that GVWR is NOT included in that calculation.

DISCLAIMER: The views and opinions expressed here are solely that of my own and are not representative of Ford Motor Company or its affiliates.

quote: If you're towing a load that's greater than the tow vehicles GVWR, which if you're towing anything you are, you ARE overly relying on the trailers brakes! LOL! The tow vehicle is NOT designed to brake anything over its own GVWR.

You miss my point... somewhat completely! :-)

See the other post above - the trailer brakes in straight lines (well, they are supposed to), but the tractor may want to turn. If the trailer >> tractor, then you have issues.